I'd like to propose a formal change to this concept of "ownership". In any future sales the artist gets a certain percentage of the gains realized. ...

I would extend this right to share in the gain indefinitely into the future, even after the original artist is dead. ...

In my scheme, when there is no direct line to the original artist, the royalty from the resale would go to a fund that is used to promote the arts and/or conserve other historical artifacts.

Droit de suite (EU directive) - citations

What distinction between "author" and "creator" do you intend?

Why shouldn't the creator benefit from his work the same as an author?

If it is to emphasize the reproducibility of a form of an original work (predicating useful life and future income) I would say the distinction is not useful. The number of art works (or IP) created that are reproducible far exceed those that are singular or limited editions such as "masterpieces," installations, and archaeological artifacts. Forms of modern art are historically distinguished precisely by applications of mass production technologies to their conceptualization and realization.

If it is to differentiate forms --literature : all other forms, author : creator, respectively-- I would say again the distinction is not useful. For you are discussing a commercial relationship between creator and types of consumers such as licensees and "cover bands" who enjoy or financially benefit from derivative uses in (reproduction of) the original work --copyrights.

Diversity is the key to economic and political evolution.